Sun is 35. Since=cos(90-x)
Answer: The salon charges $16 for a manicure and $25 for a pedicure.
Step-by-step explanation:
Let x represent the amount charged by the salon for a manicure.
Let y represent the amount charged by the salon for a pedicure.
Over the weekend, they performed 49 manicures and 16 pedicures, bringing in a total of $1,184 in receipts. It means that
49x + 16y = 1184- - - - - - - - - - 1
So far this week, they have administered 31 manicures and 33 pedicures, with receipts totalling $1,321. It means that
31x + 33y = 1321- - - - - - - - - - 2
Multiplying equation 1 by 31 and equation 2 by 49, it becomes
1519x + 496y = 36704
1519x + 1617y = 64729
Subtracting, it becomes
- 1121y = - 28025
y = - 28025/- 1121
y = $25
Substituting y = 25 into equation 1, it becomes
49x + 16 × 25 = 1184
49x + 400 = 1184
49x = 1184 - 400
49x = 784
x = 784/49
x = $16
4. $7.19 (simply just subtract the two)
The equation is y = 20(1.40)^x
where x is the number of days and y is the future amount after x days go by
The 1.40 is from the fact that 1+r = 1+0.40 = 1.40, where r is the decimal form of 40%, so r = 0.40
-----------------------------
Plug in x = 7 to get
y = 20(1.40)^x
y = 20(1.40)^7
y = 210.827008
y = 211
We round to the nearest whole number since it doesn't make much sense to have a fractional portion of an algae. After 7 days, there are about <u>211</u> algae.
